Posthole digger



May 22, 1956 CANNON 2,746,720

POSTHOLE BIGGER Filed Dec. 23, 1952 2 Sheets-Sheet 1 INVENTOR FRED F. CANNON BYWM AT TORNEY F. F. CANNON POSTHOLE DIGGER May 22, 1956 2 Sheets-Sheet 2 Filed Dec. 25, 1952 FIG. 2

FIG

INV ENTOR F R E D F C AN N ON ATTORNEY United States Patent POSTHOLEDIGGER FredF. Cannon, Erazeyhurg, Ohio Application December-.23, 1952, :Serial No. 327,577

1 Claim. (Cl..255--.19)

This invention relates tothe reaction of structures including the preparation of the foundations thereof. More particularly the invention is directed to tools and implements used, such as'thosebymeans of which laborious opless unsatisfactory .or difficult to operate and has been relatively expensive and difficult to obtain for small operations about the home, farm and elsewhere. Accordingly, the digging of posth'oles without appropriate equipmenthas been both time consuming and laborious, and

has made it desirable to have easily available equipment of this character at moderate expense.

An objectof the invention is to overcome the problems enumerated and to provide relatively simple, inexpensive portable equipment by means of which postholes can be quickly and inexpensively dug.

.Another object of the invention 'is to provide power driven post'hole drilling equipment which maybe easily moved on location.

A further object of the invention is to provide portable drilling equipment in which the drill is subject to and is driven through a suitable transmission from an internal combustion engine or other .source of power mounted above thedrill in a manner to apply weight to the drill during operation of the same.

Further objects and advantages of the invention will become apparent from the following description and in conjunction with the accompanying drawings in which:

Fig. 1 is a perspective illustrating one application of the invention.

Fig. 2, a top plan view of the drill rig per se;

Fig. 3, a side-elevational view of the device as shown in Fig. 2;

Fig. 4, a rear elevational view of the device of Fig. 3;

Fig. 5, a fragmentary sectional detail of the coupling between the drill and the driving mechanism;

Fig. 6, a perspective of the detachable cutting blade for the drill;

Fig. 7, a detail of the detachable drill point, and

Fig. 8, a section on line 8-8 of Fig. 7.

Briefly stated the invention is adapted to be mounted on a vehicle such as a truck or the like by means of appropriate supporting mechanism in the form of a crane, derrick or the like having a cable which supports the complete rig, a telescopic brace being employed for resisting the torque.

This rig comprises a double V-frame supporting a platform or motor base plate on which a gasoline engine or other source of power is mounted. The power shaft of this gasoline engine or the like has a pulley engaged by a belt which drives a larger pulley fixed on a stub 2 shaft which also has fixed thereon a sprocket of relatively small size. This sprocket is engaged by a chain by means of which al'arger'sprocket mounted upon a transmission shaft drives the latter.

The transmission shaft extends into a housing and drives, through conventional gearing or transmission, a drill shaft collar or sleeve which in turn is secured by means of a shearing pin to the end of the stem of 'a drill having a detachable drill point at its lower end, also one or more replaceable cutting blades.

'In this construction the more or less self-contained drilling apparatus is mounted for easy operation and direct application of weight to the drill during such time. Further, the device can be easily transported from place to place.

'With continued reference to the drawings the present invention is adapted to be applied to a'truck .10 or other vehicle and to support an object by means of a crane or derrick from such vehicle. The support may be three supporting arms 11 forming a .boom attached to a bracket 12 having a shaft 13 supporting a pulley about which a cable 14 extends from the truck.

The cable '14 is connected to a bar 15, supporting spaced V-frames 16, one at each end, which V-frames are connected to a .platform or motor base plate 17 on which a gas engine 18 or other source of power is adapted to be mounted. The gasoline engine has a crank case including a clutch housing 18A, which carries a conventional clutch mechanism operated by oscillatable shaft '18B, which operates a conventional forked lever, which cooperates with a clutch throw-out bearing (not shown), and is actuated by a conventional hand lever 18C, which is provided with an aperture at its upper end by means of which one end of a link 21 is pivotally connected to the lever 18C. Extending outwardly from the clutch housing 18A is a power shaft 19, on which a pulley 24 is fixed by any suitable means. The other end of the link 21 is pivotally connected to an offset lever 20, which .is pivotally connectedt'o an angle member 20A, which is secured to a downwardly extending plate 20B, which is secured to the base plate 17, the angle member 20A being secured to the plate 2'0B by suitable means such as bolts and the like and such angle member 20A being connected 'by a bar ZOC-exten'ding to a similar angle member 20A, secured to a similar downwardly extending plate 208'. The lower end of the lever 20 receives a bent over end ofa control rod '22 .for pivotal connection, such rod 22 being guided by means of a strap 22A, projecting downwardly fromthe plate 2013. The rod 22 is provided wtih a handle 23 for operating such rod and thereby the pivotal lever 20, link 21 and the clutch operating hand lever 18C, whereby power is connected from the engine 18 to the power shaft 19 at any desired time and by means of the clutch within clutch housing 18A, whereby the pulley 24 is driven or disconnected from the drive in accordance with the requirements. A suitable clutch is shown in Patent No. 1,181,321, for example pulley 24 is mounted on the power shaft of the gasoline engine or the like and serves to drive the belt 25 which in turn transmits power to a larger pulley 26 fixed on a stub or transfer shaft 27 which stub shaft also has fixed thereon a sprocket 28 of a somewhat smaller diameter. Power is transmitted from the sprocket 28 by means of a chain 29 to a larger sprocket 30 mounted on a transmission shaft 31. A housing 32 encloses the chain sprocket drive. Power from the transmission shaft is imparted to the transmission 33, the latter being supported by brackets or arms 34.

From the transmission 33 a take-oft shaft 34A is rotatably mounted in bearings in the transmission housing 33, which housing is similar to an automobile differential, such take-off shaft carrying a bevel ring gear (not shown) which is engaged by a bevel pinion gear (now shown) which is fixed to the shaft 31 and driven by the chain 29. The take-off shaft 34A extends downwardly into a collar 35, Fig. 5, having a socket 34B for receiving the stub shaft 34A while a shear pin 37 extends through a transverse aperture 38 in the stub shaft 34A and through aligned apertures 38A in the socket 35, the socket 35 being fixed to the auger or drill stem 36.

Downwardly depending frame members 39A and 39B are mounted on the frame and arranged so that the bottom ends of the depending frame members are normally well below the lower end of the stub shaft 34A whereby such frame members serve to support the frame on a horizontal surface when the drill or auger is removed thereby permitting storage and servicing of the power unit. Cross members 39C and 39B, respectively, connect the lower ends of frame members 39A and 39B. The downwardly depending frame members 39A and 39B also serve as handles to facilitate the positioning of the drilling unit so that such drilling unit may be additionally guided by hand as well as being guided by the boom including the supporting cable 14 and the telescopic arm 48, said telescopic arm being formed of a tube connected by a slotted attaching plate 51. A rod 48A telescopes.

within the tube and is connected to the apices of the frame members 16.

On the lower end of the drill stem 36 is an auger or bit having one or more replaceable cutting blades 40, each provided with cars 41 and apertures 42 through which rivets 43 secure them in place. The drill is provided also with a detachable drilling point 44 having cutting edges 45 and a threaded shank 46 by means of which it is received in an internally threaded socket 47 in the drill.

The drill shaft 36 is disposed at right angles to the power shaft and the driving of the drill is controlled by the clutch and associated control mechanism including the linkage and the connecting rod control with the operating handle 23. This handle is disposed at an elevation where it may be operated by a person standing on the ground adjacent to the drill. Thus the suspended unit supported from the cable extending from the truck may be readily moved with the truck.

During the operation of the device, in order to limit the torque or tendency to rotate, the telescopic arm 48 is attached to an intermediate portion of the boom by means of a bolt 52 fixed to one of the supporting arms 11 and projecting through an elongated slot in a plate 51 fixed to one end of the telescopic arm 48. The opposite end of the telescoping arm 48 is provided with bifurcated arms 49 having brace means 53; said arms '4 are attached by fasteners 50 to the upper ends of the frame members 16, the connection being pivotal to permit raising and lowering of the frame members 16 while the telescoping arm 48 takes the reaction of the auger which tends to rotate the frame.

A housing 54 for the drive pulleys and another housing 32 for the end chain may be provided.

With the structure described, the weight of the rig including that of the gasoline engine and the drilling structure is directly upon the axis of the drill on account of being mounted directly above the same. This particular arrangement is especially efficient and permits the driving of the drill through relatively hard formations of shale, rock and the like.

It will be apparent to those skilled in the art that the invention is not limited to the specific embodiment disclosed but that reasonable variations are within the scope thereof, and therefore the invention is only limited as defined in the following claim.

What is claimed is:

A post hole digger comprising a boom arranged at an inclination to the ground, a pulley adjacent the end of the boom, cable means extending around the pulley, a

frame having upstanding V-shaped side members connected at their upper ends to the cable, a platform supported adjacent the lower ends of said frame, opposite downwardly depending frame members extending from said frame, power means on said platform including a vertically extending driven shaft located between said downwardly depending frame members and terminating above the bottom of said downwardly depending frame members, means for connecting said shaft to an auger, an elongated telescopic member having bifurcated arms connected to the apices of the V-shaped side members at one end thereof, a swivel connection joining the other end of the telescopic member to an intermediate portion of said boom, said telescopic member serving to prevent rotational movement of said frame, said depending frame members constituting manual guiding means for accurate control of the auger in forming post holes in the ground, and also serving as a support on the ground or other surface when the auger is disconnected from the shaft.

References Cited in the file of this patent UNITED STATES PATENTS 1,499,938 Leedom July 1, 1924 1,507,776 Humiston Sept. 9, 1924 2,016,667 Crowell Oct. 8, 1935 2,165,754 Hornack July 11, 1939 2,320,612 Kandle June 1, 1943 2,598,565 Lagant May 27, 1952 

